Wednesday, November 14, 2018

Solutions for iPhone 7 Wi-Fi issues

Fault Description: iPhone 7 Wi-Fi, bluetooth can't be opened.

Possibility Reason:  According to the customer said, he found there exist leakage. And we confirmed that, meanwhile we found the backlight happens something wrong.

Usually, we will judge the damage of general function module will lead to leakage and rapid power consumption. Since the Wifi function cannot be activated, it may be caused by the damage of iphone Wifi IC.


Picture 1


First, disassemble the iphone,  use DC Power supply  to power on, indicates that the current is missing, trigger more than 100 jumps. Then open the motherboard with QUICK 861DW Hot Air Rework Station  we discover it is a water machine, but before that, the customer didn't tell us .


Observe the iPhone under stereo zoom microscope and see that there is corrosion next to the Wifi. Maybe this is where the fault lies.

Picture 2

Clean corroded area with wash water, and remove corroded filter capacitor, then connected to DPS DC power supply, the current starts to jump from 100 hops. So the problem still exist. We check other places and found a small capacitor under the compass that was corroded and damaged. Use digital multimeter to measure the voltage, there is a short circuit condition. Is this the reason of error?

Picture 3

Remove the capacitor directly, measure the resistance value with a digital multimeter, and the resistance value is normal. It is also right after power-on. Install the motherboard and test, Wifi can be turned on, and the compass is back to normal. So dark backlight is due to screen. Fault have been removed, this repair work is over!




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